384 BULLETIN 50, UNITED STATES NATIONAL MUSEUM 



most primaries definitely emarginated on the inner web, the fifth 

 sinuated; wing very rounded, the longest primaries (third to fifth 

 from the outside) exceeding the longest secondary by less than 15 

 mm.; all the rectrices black crossed by a narrow (10 mm. wide) band 

 of white about two-thirds of their length from the base, this white 

 band becoming wider on the inner webs of the three outer (lateral) 

 pairs of rectrices, occasionally a second incomplete band near the 

 base; entire underparts pure white except for a few very fine, faint 

 plumbeous shaft streaks on the sides of the throat and breast; iris 

 golden yellow; cere, rictus, and base of mandible bright orange red 

 to deep orange-yellow; basal two-thirds of mandible and inferolateral 

 angle of maxilla pale yellow, the rest of the bill slate black; feet deep 

 orange to reddish orange, claws black. 



Young (sexes alike) ^^. — Similar to the adult but with the sides of 

 the throat and the entire breast with narrow deep neutral gray shaft 

 stripes; occasionally with the inner webs of the lateral (outermost) 

 pair of tail feathers largely whitish basally, washed terminally with 

 pale fuscous and incompletely or irregularly banded with fuscous 

 black; the under side of the remiges barred on the terminal half. 



Natal down. — Not known. 



Adult male.— Wing 165-184 (179); tail 127-137 (132.4); culmen 

 from cere 18-20 (19.2); tarsus 55-64 (60.1); middle toe without claw 

 31-33 (31.8 mm.).^" 



Adult female. —Wing 183-202 (195.2); tail 126-148 (135.7); culmen 

 from cere 18-21 (20); tarsus 57-66 (61.6); middle toe without claw 

 31-37 (33.8 mm.).«^ 



Range. — Resident in the Tropical zone from southern Honduras 

 (Segovia River); south probably through Nicaragua (no definite 

 records found) ; Costa Rica (Valza, Old Harbor, Talamanca, El 

 Hogar, Guacimo, Cariblanca de Sarapique, Rio Sicsola) ; Panama 

 (Veraguas, Laguna de Pita, Punta de Sabana, Almirante, Perme, 

 Ranchon), to western Colombia (Remedios, Antioquia, Bagad6, and 

 Los Cisneros), and to northwestern Ecuador (Paramba and San 

 Javier) . 



Type locality. — ^Caribbean slope of the Isthmus of Panama along 

 the line of the railroad. 



Leucopternis semiplumbeus Lawrence, Ann. Lye. Nat. Hist. New York, vii, 1861, 

 288 (Panama; coll.).; ix, 1868, 133 ("Val," i. e., Valza, Costa Rica).— 

 Frantzius, Journ. fiir Orn., 1869, 368 (Costa Rica). — Ridgway, U. S. Geol. 



83 In the present state of our knowledge of this species it is not possible to tell 

 whether there is an immature plumage distinct from the juvenal one. We can 

 only tell adults from younger birds. 



^* Seven specimens from Panama and Costa Rica. 



*' Fourteen specimens from Panama, Costa Rica, and Nicaragua. 



